Local SEO
Proximity you cannot change, prominence and relevance you can.
What actually drives map pack placement?
Three things, and Google says so plainly in its Local ranking factors: how close the searcher is, how prominent the business is, and how relevant it looks for that query. Proximity is fixed, so the work is entirely in the other two: a complete and active
Google Business Profile guidelines listing, a steady flow of recent reviews, name-address-phone consistency across the web, and location pages that say something.
Do location pages work?
Real ones do. A page per suburb with the name swapped in is a liability and Google has been good at spotting it for years. A page that references actual jobs done there, local conditions, travel time and specific service coverage earns its place, and is much harder to produce, which is the point.
How many reviews?
Enough to compete with whoever currently holds the map pack in that area, and recent. Twenty from the last six months outperform eighty from four years ago. Velocity matters more than total.